Macro Critters of Mabul, Kapalai and Semporna

The animal

Mabul and Kapalai islands

A 45-minute speedboat ride from Semporna, the sand flats of Mabul and Kapalai hold some of the highest concentrations of marine micro-fauna. You will spend your bottom time hovering close to the seabed looking for blue-ringed octopus sheltering in empty shells. These extreme micro-species are a realistic target on most stays, and you will be glad you made the journey to photograph them.

Mabul Island sits on the edge of the continental shelf. The diving here represents classic offshore macro diving. The island has shallow reef profiles and gentle slopes of natural volcanic sand. You will find patches of healthy seagrass and massive artificial reef structures. Visibility typically ranges from 5 to 15 metres. This environment filters out the large pelagic sharks you see at Sipadan. The animals here are smaller and rely on camouflage to survive. Divers spend their bottom time hovering close to the seabed.

Kapalai is a submerged sandbank between Mabul and Sipadan. The mid reef area features sandy flats and low coral pinnacles at depths between 5 and 25 metres. You will see stingrays and schooling barracuda in the shallows. The Semporna mainland offers a different experience. The sites in the Semporna Straits and on the fringes of Bum Bum Island consist of dense silt and mud. The water here contains large amounts of discarded human-made material. The lower visibility suits a slow search close to the seabed. Divers come specifically for a concentration of rare sea slugs that eclipses Mabul amid floating plastics and thick runoff. The fauna has adapted to use the discarded tyres and glass bottles for shelter. Semporna is a noisy municipality lacking pedestrian facilities but the waters beneath the commercial jetty hold an unparalleled density of unusual sea slugs. The furthest dive sites on the mainland are a 30-minute boat ride from the harbour. The guides scour the substrate and locate specific pieces of coral rubble containing target animals. Ask your guide to show you the animal where it lives so you can compose the shot without moving it or its shelter.

Volcanic sand and debris

The nutrient runoff from the mainland and the shelter provided by debris create a nursery for micro-fauna. The Semporna straits act as an evolutionary incubator for extreme micro-invertebrates. The animals adapt to the unusual substrate and use human refuse for camouflage and reproduction. A blue-ringed octopus frequently shelters inside an empty glass bottle on the sand. Cephalopods lay their eggs inside discarded jars. The Semporna mainland sites support tiny invertebrates alongside juvenile turtles in the seagrass around Bum Bum Island.

The volcanic sand at Mabul provides a soft substrate for animals to bury themselves. The seagrass patches offer cover for juvenile turtles and benthic pipefish. The artificial reefs provide hard surfaces for corals to grow on. The combination of sand and structure supports a high density of small predators and scavengers. The environment faces challenges from illegal practices. Blast fishing is a severe hazard in the immediate Semporna area. Divers sometimes hear underwater detonations during their bottom time. The shockwaves are occasionally close enough to cause mild physical discomfort. Environmental organisations estimate that blast fishing will cause significant economic loss due to habitat destruction over the next 20 years. Acoustic monitoring devices help detect blast fishing and protect seabed habitats.

Cephalopods and rare nudibranchs

The region supports the most sought-after macro subjects in Southeast Asia. The flamboyant cuttlefish inhabits the open sand flats of Mabul and Kapalai. You will see it walking across the seabed using modified arms instead of hovering in the water column. It flashes bright yellow and maroon warning colours when threatened. The best aposematic colours are displayed during hunting strikes. The flesh contains traces of tetrodotoxin so the display is a genuine warning. The blue-ringed octopus is another venomous cephalopod you can find on the sand. It is often no larger than a golf ball. The iridescent blue rings illuminate brightly when the animal is stressed or hunting. The mimic octopus and the coconut octopus also live on the sandy bottoms around Mabul. These cephalopods are a realistic target on most stays.

The frogfish is a master of camouflage. The painted frogfish is regular on the muck sites. You can find them from the juvenile crybaby stage to mature adulthood. The adults exhibit colour bursts and frequent yawning behaviour. The green jewel cryptic frogfish is an exceptionally rare variant found deep in the rubble of the Semporna Straits. Photographers focus tightly on the eye and the luring apparatus to capture the animal. The luring apparatus mimics a small fish to manipulate the prey.

Ghost pipefish hide in the seagrass and the coral rubble. The robust ghost pipefish is found on Mabul. The Semporna mainland holds the leafy seadragon pipefish. This benthic pipefish mimics strands of dead seagrass swaying in the shallow coastal surge.

The Semporna mainland is the capital for rare nudibranchs. The Pikachu nudibranch is a bright yellow and black species that is highly photogenic and relatively slow-moving. The gold and gemmy Melibe has a translucent body and expands its oral hood to feed. The ruby Stiliger is a deep red sap-sucking slug that is barely visible to the naked eye. The wider Coral Triangle has over 1,080 documented species of nudibranchs.

The rubble holds unusual crustaceans as well. The granular pearl purse crab resembles a sugar-coated cracker. Its camouflage relies entirely on immobility. The mismatched pompom crab carries small anemones in its claws for defence. It retreats under rocks and requires patience to photograph when it emerges. The one-armed Polyonyx is a commensal crab with a massively oversized claw that lives inside tube anemones.

The resort house reefs

The resorts at Mabul have excellent house reefs located just off their jetties. Paradise I and Paradise II are the house reefs of Sipadan Water Village and Borneo Divers. The depth ranges from 5 to 18 metres over sand and coral rubble. These sites feature artificial reef structures that attract a lot of life. You will find ghost pipefish and juvenile cuttlefish here. Crocodile Avenue is located northwest of the SMART jetty on Mabul. The site consists of gentle slopes of natural volcanic sand between 5 and 20 metres. The conditions are calm and you will see seahorses and garden eels.

Lobster Wall is a submerged drop-off near the Seaventures dive rig. The depth drops from 25 to 80 metres down a vertical wall with caverns and overhangs. The wall has high concentrations of soft corals and pygmy seahorses. Semporna mainland operators use sites within a 30-minute boat ride of the harbour. The fringes of Bum Bum Island sit opposite the Tun Sakaran Marine Park. The sandy bottom and patchy seagrass here are excellent for ghost nudibranchs and rare pipehorses. The mainland muck sites have fine silt and seagrass so excellent buoyancy is mandatory.

The shallow coral rubble

The mating dance of the mandarinfish is a highlight for many photographers. Mandarinfish are heavily pigmented fish that inhabit the shallow coral rubble. They lack scales and secrete a toxic mucus to deter predation. The mating ritual occurs strictly at dusk between 5:30pm and 6:30pm. Pairs rise from the rubble as the light fades. They align their bodies and release gametes into the water column. The house reefs at Paradise I and Paradise II are excellent locations for the dusk dive. You can often see multiple pairs spawning on a single dive.

Mandarinfish are intensely photophobic during their mating ritual. Standard bright white focus lights will abort their spawning behaviour instantly. You must use red light filters on your focus lights. Strobes should only be fired at the exact moment of the mating rise. Rapid-fire flashing blinds the fish and disrupts the reproductive cycle. Be sure to arrive at the rubble patch early and settle your buoyancy before the light drops. The picturesque dragonet offers an alternative to the mandarinfish. You will find them in the shallow rubble near the jetties. They are particularly active in the late afternoon and provide a localised Semporna offering.

The micro-fauna habitat

High-end macro diving requires excellent buoyancy control. The sites consist of fine silt and sand. You must never touch the substrate. Poor buoyancy will stir up the silt and ruin the visibility for other photographers. Crushing the micro-fauna is a real risk. The blue-ringed octopus is highly cryptic when resting and can be inadvertently crushed.

You must never move an animal or poke it to get a better photograph. Harassing a blue-ringed octopus to force its rings to flash is a severe violation of dive safety and environmental ethics. A flashing octopus is a highly stressed animal issuing a final warning. Keep at least 30 to 50 centimetres between you and the octopus. Approach a flamboyant cuttlefish low and slow. Never provoke the cuttlefish to induce its warning display. The animals expend vital energy when they are stressed.

Macro lenses and lighting

Macro photography demands specialised equipment and immense patience. The ruby Stiliger requires optical snoots and heavy diopters to capture. Guides use accessible compact cameras such as the Olympus TG series paired with micro-fisheye lenses to shoot extreme macro. The Inon micro-fisheye lens is useful for capturing a tiny subject within its broader environment. You can photograph Jakobson's Phyllodesmium directly beneath the dive vessel to capture both the micro-subject and the macro-environment.

A dedicated macro lens like a 60mm or 105mm is essential to achieve a tight shot of a blue-ringed octopus without getting dangerously close. The leafy seadragon pipefish requires a very shallow depth of field to isolate its unusual form. The rosy Miamira nudibranch needs specific strobe lighting techniques to capture its deep pink hues without blowing out the highlights. The candy land Phyllidiopsis is best photographed straight down for geometric symmetry. The peachy lemon Favorinus is an egg-eating specialist so you should wait to capture it feeding on the egg ribbons of other sea slugs.

You will often spend an entire 60-minute dive moving no more than 10 metres across the sand. Semporna's macro sites are a biological treasure hunt and photographic success requires absolute trust in your guide. The guides possess an instinctual knowledge of the micro-muck environment. They can spot animals that are virtually invisible to the untrained eye.